This research involves the study of the influence of maternal undernutrition on the development of synaptic plasma membranes (SPM), the formation and structure of SPM gangliosides and glycoproteins and the activity of SPM and brain Na ion K ion ATPase. An alteration in either the synthesis or structure of SPM gangliosides or glycoprotein could result in altered synaptic connectivity and neural dysfunction. Synaptic function might also be affected by an alteration in either the quantity of SPM or in the activity of Na ion K ion ATPase. This laboratory has recently demonstrated that maternal undernutrition during lactation results in decreased content of SPM protein and decreased total activity of brain and SPM Na ion K ion ATPase in developing offspring. An analysis of the distribution of radioactive fucose among SPM glycoproteins, separated by SDS gel electrophoresis demonstrated only minor abnormalities. Future studies will include SPM ganglioside biosynthesis. They will also include similar studies of prenatal or prolonged postnatal undernutrition.